On Tue, 28 Oct 2003 07:31:12 +0000, Jim Woodward wrote:



Finally, FYI:
Martec AutoStream 6000 series $3,000
MaxProp 70322, $3,035
(Both three blade, bronze, 22" for 1.375" shaft)
Other sizes may differ. Martec's stainless series are cheaper, but
I'm not sure I'd want a stainless prop.

http://www.martec-props.com/prices-feathering.htm
http://www.pyiinc.com/?section=brows...sku=70322&sn=5



First, I wonder if the popularity of the MaxProp is because it is US made,
whereas the AutostreaM is made in Australia. Check out:
http://www.seahawk.com.au/ (the REAL website for AutostreaM)

Second, why not a SS prop? Most powerboaters regard a SS prop as "top of
the line" (of course they're usually comparing to aluminum...). The SS
prop has no "give" so it can utilize advanced foil designs like cupping
better (again, mainly compared to aluminum, but I'd probably add composite
to this). Also, my SS shaft seems to be less susceptable to electrolysis,
corrosion, and marine growth than my Campbell Sailor bronze.

Not saying you're wrong, just wondering why you wouldn't want a SS prop.

Lloyd Sumpter
"Far Cove" Catalina 36

First, MaxProp is made in Italy, the home of Ferrari and Fiat, so I'm
not sure how the place of origin cuts as against Australia.

Second, perhaps I have the old fogey's prejudice against using
stainless underwater. Shafts are one thing -- they're simple, one
piece, no moving parts (as it were). A feathering propeller is much
more complex. I'd worry about crevice corrosion and galling.
(Galling is the micro-welding of one metal part against another.
Stainless is very prone to it, as you've probably learned if you've
run a lot of stainless nuts onto stainless machine screws dry,
particularly if there's any fiberglass dust around).

Galvanic corrosion is also an issue. Bronze is more noble than most
other metals used on a boat, so a bronze propeller is automatically
safe. A stainless prop would possibly be subject to problems from the
shaft (probably not the same alloy) and other pieces.

Finally, bronze is much easier to repair. A propeller shop can do
wonders with bronze, adding material, reshaping dents and bends...
Stainless is much harder to work.

As I say, maybe this is just old predjudice. One of the troubles and
joys of our sport is that many aspects of it are difficult to analyze
completely, so we tend to do things the way they've always been done.
As I've said many times, I'm no Luddite, far from it, but I don't see
a convincing reason to use a stainless prop.

All of this is less of an issue with a fixed prop on a powerboat.
And, I'm not sure I care what most powerboaters think. There are
certainly powerboaters (including, perhaps, me) who are well informed
and whose opinion I solicit, but the vast majority don't know top of
the line from junk.

Jim Woodward
www.mvFintry.com

"Lloyd Sumpter" wrote in message .. .
On Tue, 28 Oct 2003 07:31:12 +0000, Jim Woodward wrote:



Finally, FYI:
Martec AutoStream 6000 series $3,000
MaxProp 70322, $3,035
(Both three blade, bronze, 22" for 1.375" shaft)
Other sizes may differ. Martec's stainless series are cheaper, but
I'm not sure I'd want a stainless prop.

http://www.martec-props.com/prices-feathering.htm
http://www.pyiinc.com/?section=brows...sku=70322&sn=5



First, I wonder if the popularity of the MaxProp is because it is US made,
whereas the AutostreaM is made in Australia. Check out:
http://www.seahawk.com.au/ (the REAL website for AutostreaM)

Second, why not a SS prop? Most powerboaters regard a SS prop as "top of
the line" (of course they're usually comparing to aluminum...). The SS
prop has no "give" so it can utilize advanced foil designs like cupping
better (again, mainly compared to aluminum, but I'd probably add composite
to this). Also, my SS shaft seems to be less susceptable to electrolysis,
corrosion, and marine growth than my Campbell Sailor bronze.

Not saying you're wrong, just wondering why you wouldn't want a SS prop.

Lloyd Sumpter
"Far Cove" Catalina 36

Jim Woodward wrote:

First, MaxProp is made in Italy, the home of Ferrari and Fiat, so I'm
not sure how the place of origin cuts as against Australia.

Having once been the owner of a 1985 Farrari 328 GTB I can state with
some authority that Austrailia is at a distinct advantage here. Martec
could ship parts via Thor Higerdal and they would get here faster than
they would from Modena.

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

One area where stainless, or even monel if you can get it that way is far
superior than bronze and that's if you are around Mississippi River/Delta or
similar very much. The silt in the water will chew up blades and for that
matter impellers et. al. faster than you can change them. Bronze for clean
water application but if there's any chance of "Big Muddy itis" the extra
cost of stainless is a better choice. Not a concern for most I trust.
Which brings up a follow on question. Are anhy of these props made in
Monel?

Michael